As for an illumination device which emits a ring-shaped light by an incident light from a point-like light source, there is an illumination device shown in Patent Document 1.
However, in a case wherein a light is simply entered into the light-guide member having an annular shape from one portion to illuminate the entirety of the light-guide member, an incidence portion side brightens up, so that the entirety of the light-guide member cannot be uniformly illuminated.